It's very common for directors to indulge themselves after winning awards, using the heft of their new-found acclaim to splash out on a pet project. And considering how long Martin Scorsese had to wait for his Oscar, no-one could complain about him letting his hair down and doing something a little less cerebral. While it never reaches the heights of his earlier work, Shutter Island is a fun and engaging thriller which more or less holds together, and which is made with the same affection for its genre as Peter Jackson's remake of King Kong.The comparison with King Kong extends further than just two great directors kicking back a little. Both Jackson's remake and Shutter Island are upmarket re-workings of rich B-movie traditions, namely the monster movie and the asylum-based thriller. Both take films or genres which are well-worn or familiar, and re-imagine their stories as they would have been told had the technology or the money been available the first time around.

The core ideas in Shutter Island are easily recognisable to film fans, and even casual Scorsese-ites will be able to spot the master returning to old themes. The idea of a mental institute in which the lines between patients and doctors are blurred is a big lift from Shock Corridor, or its slightly more upmarket cousin The Ninth Configuration. The idea of foul play involving Nazi or ex-Nazi scientists is taken from The Boys from Brazil, which itself was rather ripe. And the device of an island or isolated location being cut off by the elements is as old as the trees; Stanley Kubrick was pastiching it when he made The Shining.This revamped B-movie aesthetic is reinforced by Shutter Island's pulpy, glossy visuals. The film is often art directed to within an inch of its life, as Scorsese seeks to wring out every inch of suspense and terror from the claustrophobic setting. Like The Killer Inside Me shortly after it, Shutter Island's visuals are rooted in 1950s noir, not just in costumes and lighting decisions but in the measured and deceptive staging of certain sequences. Scorsese utilises every possible camera angle to tell the story, from tough dolly shots when the German soldiers are executed, to tight zooms on the spiral staircase which recall the ending of The Red Shoes.

As if you needed any more convincing that this is not a 'serious' work, you only have to listen to the dialogue in the first 30 minutes. The running of the island is explained in such a way that you know which elements will come into play later on. And there are a number of deliberate continuity errors which are common in low-budget films, such as glasses disappearing and re-appearing. The film is edited by Thelma Schoonmaker, widow of Michael Powell, and both she and Scorsese are too talented to let such things slip by unnoticed.The central idea or twist of Shutter Island is that of people pretending to be other people, and living out their lives as highly complicated fantasies or repetitions of past lives. Again, we are on familiar ground, not just with The Shining but with Roman Polanski's The Tenant. Both of these films succeed by completely disorientating their audiences: the goalposts are constantly shifting and what seemed a watertight explanation ten minutes ago is no longer anything of the sort. On a slightly lesser note, the actual revelation involving Teddy Daniels' name is a clouded reference to Robert De Niro's character in Angel Heart.All that has been said so far makes Shutter Island out to be a failure, a film packed with enough references to satisfy fanboys but nothing for the uninitiated. Considering that so much of the film is well-worn to the point of being ridiculous, and that is knowingly well-worn at that, the film must then succeed or fail on whether or not it is entertaining and thrilling in its own right. And broadly speaking, it's is, albeit not completely.

The most illuminating comparison is with The Ghost Writer, another Polanski film which is also at heart an old-fashioned thriller. Both Polanski and Scorsese are fantastic visual artists, who know how to use colour and music both thematically and symbolically, and who can achieve a real sense of thrill whatever the subject or situation. But The Ghost Writer is the superior film because it is much more certain of its own purpose and identity, not just in terms of its politics but as a piece of genre filmmaking. The Ghost Writer is so constantly aware of what it wants to be, and of the manner in which it wants to achieve that, that even when aspects like the final twist don't quite work, it still feels reasonably sure-footed.Shutter Island, for all its knowing ripeness and unapologetic B-movie trappings, can't quite make up its mind how serious it wants to take itself. For its first half hour, where the dialogue is expository to the point of being parody, you are expecting a kind of knowingly cheesy film in the manner of High Anxiety. But as the various plot twists start to unfold, including some very graphic dream sequences involving murdered children and the Holocaust, we begin to feel like the film is wanting to carry more weight that its setup seems to allow.

To its credit, most of Shutter Island does hold together rather well. The dream sequences involving Teddy Daniels' wife and children are beautifully done; seeing his wife turn slowly to ashes as the house burns is very striking. And taken purely as a thriller, it is an exciting romp with a series of plot points which fit together while throwing us off. The scenes of Leonardo DiCaprio wandering along dark corridors by match-light are like the action sequences in The Time Machine married to the haunted house traditions of The Haunting or Alien.On the other hand, as many reviews have pointed out, the final reveal involving Teddy's true identity is somewhat disappointing. It's not that the twist comes out of nowhere and makes no sense, nor conversely that we could see bits of it coming a mile off. The disappointment comes from the fact that we have to definitively settle for one version of events over another; once we leave the lighthouse, the sense of threat has largely gone. It would have been braver and more effective to have left the audience hanging, to decide for themselves whether Teddy was real or not. There is not the same level of ambiguity as in The Shining, or Inception, or indeed Mulholland Drive. But it would have satisfied both the conventions of the genre and created enough debate for a couple of water-cooler moments.The performances in Shutter Island are as ripe and enjoyable as the material. DiCaprio may have assumed Robert DeNiro's mantle as Scorsese's actor of choice, but his performances have been much more larger-than-life than his predecessor. While his Howard Hughes in The Aviator occasionally drifted into pastiche, here he is in full-on scenery-chewing mode, playing up every emotion and being constantly on edge. Ben Kingsley and Max von Sydow are clearly enjoying themselves, revelling in the chance to play with the material and send up their earlier, 'serious' selves. And Mark Ruffalo is also solid, even if his role does become more of a cipher as things play out.Shutter Island is ultimately a good fun thriller which is a great deal more stimulating than Quentin Tarantino's efforts at B-movie homage. It's not a 'serious' or 'proper' Scorsese work both by design and execution, but it is slightly hamstrung by its occasional desire to take itself a bit too seriously for the circumstances. In all it's an enjoyable, atmospheric work crammed with enough suspense for thriller fans, enough references for film geeks, and just about enough entertainment for the rest of us.